Karyolysus sp. (Haemogregarinidae, Adeleida, Apicomplexa): Host‐Parasite Relationships of Persisting Stages

Abstract

ABSTRACT. Two persisting stages in the life cycle of a hemogregarine Karyolysus sp. are described from the liver and blood cells of its intermediate host, the lizard Lacerta raddei nairensis. The tissue cell merozoites lie in a parasitophorous vacuole. Despite the protective role of the vacuolar membrane, the intracellular parasites are progressively destroyed and eliminated during the autumn and winter. Some of the merozoites that normally survive within the host cell even in cold seasons appear to be surrounded by another type of parasitophorous vacuole which is connected to the intercellular space by narrow channels. The intraerythrocytic gamonts that persist in the circulating blood are encapsulated and undergo progressive, obvious structural changes. The two persisting stages are compared with hypnozoites of other Sporozoa.

Haematozoan parasites of the lizard Ameiva ameiva (Teiidae) from Amazonian Brazil: a preliminary note

“…It is of interest that they are strikingly similar to parasites the senior author described in the spleen of birds infected with Atoxoplasma, a parasite he considers to also be a lankesterellid (Lainson 1959). The stock-piling of extra-erythrocytic merozoites in reticulo-endothelial cells of the internal organs is a feature of some haematozoa, and has been considered to be a mechanism providing latent ("sleeping") forms in conditions unfavourable for the two-host life-cycle (Beyer & Sidorenko 1984).…”

Ultrastructure of developmental stages of Hemolivia stellata (Apicomplexa: Haemogregarinidae) in the cane toad Bufo marinus and in its vector tick Amblyomma rotondatum

“…Encapsulated gametocytes with similar processing faults, but no demonstrated presence of sutures, have been seen in the``Karyolysus'' sp. of Beyer and Sidorenko (1984) and in H. canis (Droleskey et al 1993;Murata et al 1993). Gametocyte walls of other species of Hepatozoon are apparently not thick enough to interfere in processing, and allow a more detailed view of TEM images (Stehbens and Johnston 1967;Paterson et al 1988;Lowichick et al 1993).…”

“…Gametocyte walls of other species of Hepatozoon are apparently not thick enough to interfere in processing, and allow a more detailed view of TEM images (Stehbens and Johnston 1967;Paterson et al 1988;Lowichick et al 1993). Except for storage granules, few other structures are detectable in the encapsulated gametocytes; Beyer and Sidorenko (1984) claimed a considerable reduction of cytoplasmic components occurring in the encapsulated waiting-stage gametocytes of``Karyolysus''. In our opinion, these structures were obliterated due to processing faults: TEM images of pre-and post-fertilized stages of H. mariae in the tick (Smallridge and Paperna 2000b) appear to retain all ®ne structural components seen in H. stellata premature gametocytes in the vertebrate host.…”

Morphological and molecular characterization of Karyolysus ¿ a neglected but common parasite infecting some European lizards

“…Haemogregarina was found in various species of terrapins, while Hepatozoon is the typical apicomplexan parasites found in different species of snakes and lizards [1], each distinguished by very different developmental patterns in their invertebrate hosts in which sporogony occurs. To date, Karyolysus has been reported mainly in European lizards [2][3][4][5], as well as in Asia [6]. The Svahn, 1975 and K. minor Svahn, 1975.…”